import ast sys for regex runtime build

StgSharp.RegularAnalysis/RegularMachine/Node.Branch.cs

@@ -36,9 +36,11 @@ using System.Threading.Tasks;
 
 namespace StgSharp.RegularAnalysis
 {
-    internal  class RegularBranchNode : RegularStateNode
+    internal sealed class RegularBranchNode : RegularStateNode
     {
 
+        private int _afterBranch;
+
         private int _lastBranch;
 
         private List<BranchMeasureResult> _result;
@@ -59,15 +61,26 @@ namespace StgSharp.RegularAnalysis
                              out int label
         )
         {
-            int pos = context.LastBranch.Peek();
-            if (AvailableNodes.Length > _lastBranch)
+            if (context.StateCode == 0)
             {
-                // return measure result
-                label = 0;
+                // branch match
+                label = _afterBranch;
+                _ = context.LastBranch.Pop();
+                _lastBranch = 0;
                 return true;
             }
-            label = FailNodeIndex;
-            return false;
+
+            // restore sequence position
+            int pos = context.LastBranch.Peek();
+            context.Position = pos;
+            if (AvailableNodes.Length > _lastBranch)
+            {
+                label = FailNodeIndex;
+                return false;
+            }
+            _lastBranch++;
+            label = AvailableNodes[_lastBranch];
+            return true;
         }
 
     }

StgSharp.RegularAnalysis/RegularMachine/Node.Sequence.cs

@@ -1,12 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection.Emit;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace StgSharp.RegularAnalysis
 {
-    internal class RegularSequenceNode : RegularStateNode
+    internal sealed class RegularSequenceNode : RegularStateNode
     {
 
         private string _sequence;
@@ -17,20 +18,9 @@ namespace StgSharp.RegularAnalysis
                              RegularStateNode former,
                              RegularContext context
         )
-        {
-            return true;
-        }
-
-        public override bool TryTransaction(
-                             ReadOnlySpan<RegularStateNode> nodeSpan,
-                             RegularContext context,
-                             out int label
-        )
         {
             int pos = context.Position + 1;
-            if (true) { }
-            label = -1;
-            return false;
+            return context.CurrentCharSpan[pos.._sequence.Length].SequenceEqual(_sequence);
         }
 
     }

StgSharp.RegularAnalysis/RegularMachine/StateMachine.cs

@@ -127,6 +127,8 @@ namespace StgSharp.RegularAnalysis
 
         public int Position { get; set; } = -1;
 
+        public int StateCode { get; set; } = 0;
+
         public ReadOnlySpan<char> CurrentCharSpan => Source.AsSpan()[Begin..Position];
 
         public string Source { get; init; }